Manufacture of can bodies and the like



J. MORRIS Aug. 29, i7

MANUFACTURE OF CAN BODIES AND THE LIKE 3 SheetS-Sheet l Filed NOV. 17, 1964 ug- 29, 1967 J. MORRIS 3,337,944

MANUFACTURE OF CAN BODIES AND THE LIKE Filed Nov. 17, 1964 C5 Sheets-Sheet. 2

Aug. 29, 1967 1. MORRIS MANUFACTURE OF lCAN BODIES AND THE LIKE Filed Nov. 17, 1964 5 Sheets-Sheet United States Patent O 3,337,944 MANUFACTURE OF CAN BODIES AND THE LIKE Jack Morris, Monsey, N.Y., assigner to American Machine d: Foundry Company, New York, N.Y., a corporation of New Jersey Filed Nov. 17, 1964, Ser. No. 411,863 7 Claims. (Cl. 29-413) ABSTRACT OF THE DISCLOSURE A method and apparatus for forming lengths of tubing of sheet material from an advancing strip of such material. The material is transversely slitted at spaced intervals and the slit-s are interrupted at the edges and at the mid-portion of the strip. After the stri-p has been formed and welded into tubing, the unslit opposed wall portions are substantially pressed together and the sides of the tubing where the slits have been formed are loop-like. Then, the unslit portions are cut, and the severed tube lengths are expanded.

This invention relates to the manufacture of articles of tubular sheet material, such as can bodies and the like.

It is customary to form can bodies, and like tubular members, by rapidly advancing a strip of Sheet metal, while forming same into a cylindrical tube on which the edges of the strip, after being brought together, are welded, or otherwise secured together, to form a longitudinal seam. Then the formed tubing is severed transversely into the desired lengths for forming the can bodies. However, the cutting of such flexible-walled tubing into lengths has heretofore required relatively complicated and expensive mechanisms and usually not well adapted for high speed operations, and generally such equipment has involved the necessity of introducing some form of die or anvil means into the interior of the tubing, as well as applying external cutting means.

The present invention provides a novel, relatively simple and inexpensive method and apparatus for solving this problem of severing the tubing into desired lengths accurately and at high speeds.

In carrying out the'invention, the metal strip material which is to form the can bodies, is rapidly advanced while transverse slits are cut therein at intervals spaced apart at distances equal to the desired lengths of the can bodies.

These slits, however, are interrupted at regions adjacent .v both edges of the strip and same are also interrupted at the midportion of the strip. Then, as the strip is advanced, it is shaped into the form of hollow tubing (either circular, or preferably somewhat oval-like in cross-section) and as the two strip edges are brought together, same are welded or otherwise secured to form a longitudinallyextending seam in the advancing tubing. Then, as such tubing advances, portions along the middle of the upper side are substantially flattened against portions along the middle of the underside, while avoiding flattening together the portions along both sides of the tubing, and instead leaving the side portions with curved, uncreased cross-sections. The regions where the above-mentioned slits are interrupted, will be those portions along the middle of the tubing which have become flattened together7 whereas the slits will occur at the side regions, which are still of curved cross-sections. Accordingly, at this stage, the successive tube sections may be easily severed by a cutter arranged transversely to cut the midportions of the tubing which have been flattened together, viz. the portions where the slits were interrupted, and thus the succesisve sections will become completely severed upon cutting such midportions, because the side portions of curved cross-section have already been cut apart by the ICC aforesaid interrupted transverse slits which were formed in the original strip material.

The tube sections, after being cut apart, may be expanded to the desired circularI or other cross-sectional hollow shapes and the end edges thereof may be shaped by flange-forming equipment or other means preparatory to applying the bottoms and tops of the cans.

It has heretofore been proposed to form can bodies and the like of completely flattened tubing, and while such flattened tubing may be readily cut into lengths by a blade cutting through both layers against an anvil means, yet when the flattened tubing is thereafter expanded to a rounded formation, creases or lines of weakness will remain along on the sides. By the present invention, this diculty is completely avoided because the tubing at its sides is at no point flattened so as to there crease the metal, but instead the sides remain with rounded cross-sections at these portions where the metal has been preslit, so that the difficulties of cutting flexible, rounded sections are also avoided. All the cutting that has to be done to sever the tubing into sections, occurs along the midportions of the tubing which have been flattened together.

It has also been proposed heretofore to preslit the advancing sheet strip material transversely, with the slits interrupted at the edge portions thereof, so4 that, after the strip has been formed into tubing, only the portions along adjacent the longitudinal seam need be cut apart in severing the tube lengths. But in these cases, so far as is known, it has always been the practice to cut the tube sections apart while same are in hollow tubular form, thus generally necessitating the use of either a cutting blade or anvil means located inside the tubing, with the consequent difficulties above noted. The preslitting of the strip in accordance with the present invention, with the slits not only interrupted at the edges of the strip, but also at the midportion thereof, has the advantage that the formed tubing may more readily be controlled in position as same is advanced through the apparatus without misalignment of the successive successions of tubing, because, until the sections are finally cut apart, they will be attached not only at the regions of the seam line, but at the region of the midportion of the underside of the tubing.

If desired, instead of having the slits interrupted only at oneregion along the midportion of the strip, the midportion itself may also 4be more or less transversely slitted by short interrupted slits, so that there will be less metal to Abe cut apart in the final operation of separating the tube sections. Such use lof slits interrupted at several regions may be advantageous, particularly for tubing which is of highly flexible sheet material, but of relatively large diameters.

Preferably with the apparatus of the invention, the longitudinal seams in the can bodies are formed `by welding by the use of high frequency heating current applied to the edges to be welded, just before they come together at a weld point, the current being applied either by contacts directly to such edges respectively, or, if preferred, same might be applied inductively by known methods. However, various aspects of the invention are applicable to the formation of tubular can bodies of materials other than sheet metal, for example plastic or composite sheet materials or the like, with the seam being formed -by heat sealing, crimping or other known methods. Also, while the invention is particularly adapted for forming cylindrical can bodies, yet various aspects of the invention are adapted to form sections of tubing of other cross-sections, such as polygonal forms.

Various further and more specific objects, features and advantages of the invention will appear from the description given below, taken in connection with the accompanying drawings, illustrating by way of example preferred forms of the invention.

In the drawings:

FIG. l is a somewhat schematic or diagrammatic perspective view illustrating one embodiment of the method;

FIGS. 2 and 3 are perspective diagrammatic views of two alternative forms of cutting means for preslitting the strip o-f sheet material;

FIG. 4 is a plan view of a portion of the strip material as preslit with another and preferred slit formation;

FIG. 5 is a somewhat diagrammatic or schematic perspective view of a preferred and somewhat modified embodiment of the apparatus;

FIGS. 6 to 14 inclusive are sectional views taken substantially along correspondingly numbered section lines on FIG. 5;

FIG. l5 is a view showing the tubing in cross-section and with the mid-portions flattened together ready to be severed;

FIG. 16 is a side elevational view showing in some detail one possible form of arrangement for cutting apart the tube lengths;

FIG. l7 is a perspective View of same; and

FIG. 18 is a longitiudinal vertical sectional view, partially broken away, `further showing various feaures of the arrangement of FIG. 16.

Referring now to the drawings in further detail, as shown in FIG. 1 the strip which is to form the tubing is indicated at 20, being pulled from a coil 21 thereof as by a pair of pull rolls 22. The strip then passes through preslitting means at 23, possible forms of which will be referred to hereinafter. Such slitting means acts to cut transversely-extending slits, such as indicated at 24, these slits, as more clearly appear in FIGS. 2 and 3, being interrupted at regions close to the edges of the strip, as indicated, at 25 and 26, and same are also interrupted at the mid-portion of the strip, as indicated at 27. The slits are spaced apart longitudinally of the strip by distances approximately equal to the desired length of the can bodies to be formed.

The slitting device, as shown schematically in FIG. 2, may be of a type having a vertically-reciprocating blade, as indicated at 28, which may act against anvil means, as at 29, located beneath the strip. Inasmuch as such a blade, in acting, will momentarily stop the forward movement of the strip, the strip may be conducted on past the slitting device in a sagging condition, as indicated at in FIG. 1, so that pull roll means, as at 31 maythereafter pull the strip at constant speed, even though the strip movement is momentarily interrupted at the slitting blade 28. Alternatively, as shown in FIG. 3, slitting blades as at 32, 33 may be mounted on the periphery of a -rotatable support 34 to act against suitable rotatable supporting means 35 beneath the strip.

After leaving the rollers 31, the strip passes between two or more pairs of tuble-forming rollers, such as indicated at 36, 37 and 38, 39. Upon leaving the forming yrollers, the strip edges will have been brought up and around into positions such that a V-shaped gap is formed therebtween, which becomes closed yat a weld point, such as at w. Suitable pressure applying means (not here shown) may be provided in the conventional way to bring the edges either into abutting relation at the weld point, or, if preferred, into a position with one superposed above the other, in which case rollers may be provided for forming Ia mashed lapped type of weld in known Ways. Prior to the weld point, preferably high frequency heating current is applied to the approaching gap edges. This may be accomplished inductively in known ways, or, if preferred, the current may be applied by contacts, as indicated at 40, engaging respectively the metal on the opposite sides of the gap, these contacts being connected to the terminals of a high frequency generator at 41, so that the current will flow from the contacts along the approaching edges of the V-shaped gap to and from the weld point for heating the edge surfaces to Welding temperature at their moment of arrival at that point.

At the region ofthe weld point, the tubing may be either circular in cross-section, or, preferably, `as hereinafter shown, the cross-section may be generally oval, with the upper and lower surfaces spaced apart, but substantially flattened land with the two sides, however, of the tubing still of smoothly-curved rounded cross-section.

Next, the formed, longitudinally-welded and preslit tubing is passed between the upper and lower rollers, as at 42, 43, acting to ilatten the mid-portion of the upper wall of the tubing rmly against the mid-portion of the lower wall. The resulting tubing will then have Ia contiguration such as is shown in cross-section in FIG. 15, from which it will be noted that the portions 44, 45, at each side of the tubing, will still have curved cross-sections, free of any abrupt bends or creases, and generally loopedshape. It will be noted that the previously-formed slits 24 will occur withinthese curved cross-sectional portions, whereas at the mid-portion of the underside of the tubing at 46, the slits are interrupted, as is also the case at the mid-portion of the upper surface at each side of the welded seam line 47.

The tubing in this form may then be passed between suitable means for pulling and advancing same, for example upper and lower so-called Caterpuller flexible belt means 48 and 49. The tubing then passes onto a cutting device, as indicated at 50, and a preferred form of which will be further described hereinafter. This device will act to cut the portions of the tubular workpiece transversely of the places where the slits (as initially formed) are interrupted, that is, the places where the upper and lower mid-portions of the tubing have been flattened together into contact. Since the side portions have already been transversely slit, there will, of course, be no occasion for having any cutter blade means to come into contact therewith, and thus these portions of curved cross-section, will remain smoothly curved, free of creases. In the event this device is such that, during each cutting operation it acts momentarily to stop the advance of the work, then the latter may assume a varying sagging path as indicated at 51.

The severed lengths of tubing or can bodies, as indicated at 52, may be discharged onto a conveyor 53, and carried to suitable expanding and flange-forming means, generally indicated at 54 (the construction and operation of which forms no part of the present invention). From such apparatus, the can bodies, as at 55 (now of circular or other desired expanded cross-sectional shapes) may be carried away on a conveyor 56.

It may be here mentioned that, if desired, each of the slits, as shown at 57 in FIG. 4, as formed in the preslitter, may be so formed as to terminate in small perforations 58. Thus, in case the cutting blades in the cutter 50, as they engage the work, should happen to be slightly misaligned with respect to the slits, they will still act to sever the work by cuts which will termin-ate at some point within the small perforations.

Important portions of a somewhat different embodiment of the invention will now be described in connection with FIG. 5. Here the preslit strip 60 is shown as being advanced in llat condition by suitable pull rollers 61 (see sectional View FIG. 6). The strip then passes on to engage suitably-shaped forming rollers l62 (see FIG. 7) for cooperating in imparting a channel-shape to the strip. Either at the location of these rollers, or shortly thereafter, the side portions of the strip may be engaged vby angularly positioned rollers, as shown at 63 in FIG. 8. Next, as shown in FIG. 9, the upturned side portions may be dellected inwardly toward each other by angularly-positoned rollers 64. Either at the location of these rollers, or shortly thereafter, the interior portion of the work may become engaged by mandrel means, carried by suitable supporting means, as indicated at 65, extending through the gap in the tubing being formed, and thence extending forwardly to a point near or beyond the weld point. As indicated in FIGS. 9 and 10, the mandrel may be comprised of two parts, as at 66, `67, with a space therebetween extending along beneath the gap 'between the approaching edges which are to be heated and welded together. Rollers, as at 68, are positioned to press the work downwardly.

. As shown by the sectional view of FIG. 11, if desired, the edges Ialong the tube gap may be brought into slightly superposed relation, and iinally, at the region of the weld point w, as shown in FIG. 12, the edges may be pressed together in welded relation by upper and lower rollers 69 and 70. Heating of the gap edges prior to the weld point may be accomplished as above described in reference to FIG. 1.

Alternatively, the gap edges as the weld point may be brought into alignment when closing the gap to form a butt weld. Whether the weld is a mashed lapped weld, or a butt weld, pressure rollers, as -at 70a and 7Gb may engage the sides of the tubing at the region of the weld point.

It will be understood that various of the rollers above referred to, or possibly all of the same, may be suitably driven for advancing the strip and tube in the manner above explained.

Subsequent to welding of the tube gap, the tubing (as shown in FIGS. 13 and 14) may pass between pluralities of pairs of upper and lower rollers, as at 71, 72, 71', 72', whereby the mid-portions of the upper surface are flattened against the mid-portions of the lower portion of the tubing, as per the formation shown in FIG. 15. Thereafter the tubing may be advanced and severed into sections.

While various forms of arrangements may, of course, be provided for severing the mid-portions of the tubing, which have been iiattened together as shown in FIG. 15, one suitable form will now be described in connection with FIGS 16 to 18 inclusive. Here the tubing, after assuming the cross-sectional shape shown in FIG. 15 and in a sagging relationship as indicated at 51, is passed through suitable guide means as at 75, thence through die means having upper and lower parts 76a and 76b with a longitudinal cavity extending therebetween, which cavity, as will be understood, has a cross-sectional shape such as closely to conform to the cross-section of the tubing, as shown in FIG. 15. A suitable vertically-reciprocable punch press or the like may have secured to its toolreceiving portion 77, a blade 78 mounted in a position vertically to reciprocate, as indicated in FIG. 17, at the end of the die means 76a to sever the lengths of tubing when same emerge from the cavity in the die means.

A pair of vertically-reciprocable pins 79a, 79b may be provided to extend up through a base 80 to engage the underside of the workpieces when they emerge from the die means.

The punch press apparatus may either be arranged in any suitable manner to operate with a predetermined frequency approximately equal to the frequency at which the can lengths are being advanced through the apparatus, or as will be readily understood, if preferred, the strokes of the punch press may be suitably controlled to be in step with the passage of the successive can bodies.

The punch press may be accompanied by, and -arranged to operate by, switch means 81 for closing the circuit of magnets, as at 82., which will act to withdraw downwardly the pins 79a, 79b, respectively, against the pressure of return spring means as at 83.

When the blade 78 descends and cuts off one of the can lengths, such as indicated at 84 in these fingers, the switch 81 will be closed, thereby energizing the magnets 82, and accordingly withdrawing downwardly the pins controlled thereby, thus allowing (as soon as the blade is retracted) a further can length to be pushed through the die means to emerge in position to -be severed. Upon retr-action of the blade 78, however, the magnets 82 will be de-energized and their springs will cause the pins 79a, 79b to be thrust upwardly against the underside of the next can length, just as it begins to emerge from the die means. The pins will engage the flexible and curved side portions of the can length, however, and cause same to be iiexed upwardly somewhat to positions such as shown at 85 in FIG. 18. Thus the trailing end portion at 85 of one can length will be flexed up out of alignment with the forward end edge portion 86 of the next can length, and the latter, in engaging the pins, will provide indexing or stop means at the vertical plane of the blade 78 and thus as the blade descends again, the trailing end of the can length 84 which is to be severed, and the forward end edges of the next can length, will be at the proper plane so that the mid-portions of the can lengths which have been flattened together will be severed, as best shown in FIG. 17, accurately along lines in alignment with the performed slits 24. The can lengths, after severing, may be deflected downwardly as by air jet means 87, onto suitable support or conveying means 88, or conveying means, as at 53, FIG. 1.

Although certain particular embodiments of the invention are herein disclosed for purposes of explanation, further modifications thereof, after study of this specification, will be apparent to those skilled in the art to which the invention pertains. Reference should accordingly be had to the appended claims in determining the scope of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. The method for forming lengths of tubing of flexible sheet material by advancing `a strip of such material and while shaping the same to tubular form and securing the strip edges together to -form a longitudinally-extending seam, such method being characterized in that, prior t0 shaping the strip into tubular form, transverse slits are formed in the strip at intervals spaced apart by distances substantially equal to the desired tube lengths, said slits being interrupted at the edges of the strip and at least at one other location at the mid-portion of the strip, then, after the strip has been formed into tubing having said longitudinal seam, transversely cutting the unslit portions adjacent the longitudinal seam and also the unslit midportions of the strip by cuts substantially in alignment with said slits, said cuts, together with the slits completing the severance of the tube lengths, the unslit opposed wall portions of the tubing during such cutting being substantially pressed together, while the sides of the tubing where the slits have been formed remain with loop-like crosssections unflattened, and thereafter expanding the severed tube lengths to a desired tubular cross-sectional shape.

2. The method for forming lengths of tubing of exible sheet material by advancing a strip of such material and while shaping the same to tubular form and securing the strip edges together to form a longitudinally-extending seam, such method being characterized in that, prior to shaping the strip into tubular form, transverse slits are formed in the strip at intervals spaced apart by distances substantially equal to the desired tube lengths, said slits being interrupted adjacent the edges of the strip and at least at one other and generally opposite location on the formed tubing, and the tubing being formed to have a generally oval cross-section with its major axis extending to each side of the seam, and then, after the strip has been thus formed into tubing, transversely cutting the unslit portions adjacent the longitudinal seam, and also the unslit opposite portions, by cuts substantially in alignment with said slits, said cuts, together with the slits, completing the severance of the tube lengths, the unslit opposed wall portions of the tubing during such cutting being substantially pressed together, while the sides of the tubing where the slits have been formed, remain with loop-like cross-sections unflattened.

3. Method in accordance with the foregoing claim 1, and in which, prior to cutting said unslit regions, trailing end edge portions at the slits are pressed out of alignment with corresponding leading end edge portions on the neXt succeeding tube lengths, such non-aligned edge portions thereby providing indexing means demarking the planes along which the transverse cuts are to be made.

4. Apparatus for forming lengths of tubing of flexible sheet material, comprising in combination: means for advancing a strip of such material while shaping the same to tubular form and securing the strip edges together to form a longitudinally-extending seam; means for forming transverse slits in the strip prior to its being formed into tubing and at intervals spaced apart by distances equal to the desired tube lengths, such slits being interrupted at the edges of the strip and at least at one other location at the mid-portion of the strip; means engaging the opposite Walls of the formed tubing at the unslit portions for pressing same together While the sides of the tubing where the slits occur remain with looplike cross-sections unflattened; and means for then transversely cutting said unslit portions by cuts substantially in alignment with said slits, said cuts, together With the slits, completing the severance ofthe tube lengths.

5. Apparatus for severing tubing of flexible sheet material to form therefrom a succession of tubes of predetermined lengths, said tubing having been transversely preslit at tube length intervals at opposite wall portions thereof, intervening opposite Wall portions being unslit, said apparatus comprising in combination: means for advancing the preslit tubing through the apparatus; means for pressing the opposite unslit Wall portions thereof together while the slit portions remain at either side With loop-like cross-sections; means for then transversely cutting the unslit portions with the cuts substantially in alignment with the slits, whereby the slits and cuts together complete the severance of the tube lengths.

6. Apparatus in accordance with the foregoing claim 5 and in which means is provided in advance of the cutting means for pressing the trailing end edges of the tube lengths adjacent the slits out of alignment with the corresponding `forward end edges of the next tube lengths, thus to provide misaligned edge portions, said latter means being accompanied by stop means engageable by said forward end edges to stop the movement of the tubing While the cutting means is actuated.

7. Apparatus in accordance with the foregoing claim 6 and in which means controlled by the actuation of the cutting means operatively displaces said stop means to permit the tubing to advance after each cutting operation.

References Cited UNITED STATES PATENTS 1,922,828 8/1933 Stine 29-l63.5 2,018,085 10/1935 Otte 29--160 2,444,465 7/1948 Peters 113-12 2,826,810 3/1958 Peterson 29-413 3,072,770 l/1963 Goodridge 219-8.5 3,124,872 3/1964 K nodel 228-13 JOHN F. CAMPBELL, Primary Examiner.

THOMAS H. EAGER, Assistant Examiner. 

1. THE METHOD FOR FORMING LENGTHS OF TUBING OF FLEXIBLE SHEET MATERIAL BY ADVANCING A STRIP OF SUCH MATERIAL AND WHILE SHAPING THE SAME TO TUBULAR FORM AND SECURING THE STRIP EDGES TOGETHER TO FORM A LONGITUDINALLY-EXTENDING SEAM, SUCH METHOD BEING CHARACTERIZED IN THAT, PRIOR TO SHAPING THE STRIP INTO TUBULAR FORM, TRANSVERSE SLITS ARE FORMED IN THE STRIP AT INTERVALS SPACED APART BY DISTANCES SUBSTANTIALLY EQUAL TO THE DESIRED TUBE LENGTHS, SAID SLITS BEING INTERRUPTED AT THE EDGES OF THE STRIP AND AT LEAST AT ONE OTHER LOCATION AT THE MID-PORTION OF THE STRIP, THEN AFTER THE STRIP HAS BEEN FORMED INTO TUBING HAVING SAID LONGITUDINAL SEAM, TRANSVERSELY CUTTING THE UNSLIT PORTIONS ADJACENT THE LONGITUDINAL SEAM AND ALSO THE UNSLIT MIDPORTIONS OF THE STRIP BY CUTS SUBSTANTIALLY IN ALIGNMENT WITH SAID SLITS, SAID CUTS, TOGETHER WITH THE SLITS COMPLETING THE SEVERANCE OF THE TUBE LENGTHS, THE UNSLIT OPPOSED WALL PORTIONS OF THE TUBING DURING SUCH CUTTING BEING SUBSTANTIALLY PRESSED TOGETHER, WHILE THE SIDES OF THE TUBING WHERE THE SLITS HAVE BEEN FORMED REMAIN WITH LOOP-LIKE CROSSSECTIONS UNFLATTENED, AND THEREAFTER EXPANDING THE SERVED TUBE LENGTHS TO A DESIRED TUBULAR CROSS-SECTIONAL SHAPE. 